Electric fuse plug cap



Jan. 11, 1944. R. T. BRI-mm 2,338,994

ELECTRIC Fus PLUG CAP Filed Sept. 21, 1942 Summer Patented Jan. 1l, 1944 UNITED STATES PATENT OFFICE 4 Claims.

My invention refers to devices for use on electrical apparatus and especially to means for identifying the circuit in which a fuse has been blown It is customary to provide, on the electric distribution panel, a pair of fuse plugs for each circuit leading therefrom to the various rooms, machines or other installations supplied with electricity by the said several circuits. If one of these fuses is blown it is often a matter of several minutes time before the proper fuses can be located on the said panel.

It is an object of my invention to provide an identifying means on each of the fuse plugs, in pairs.l whereby when the current has been broken by the blowing of one of the fuses, the two fuses controlling that circuit may be immediately found, without the loss of time. It is a further object of my invention to provide a removable cap for each fuse plug, said cap being made of rubber or other suitable elastic and insulating material; and being adapted to be slipped on or off the head of the fuse plug; and also having an identifying number or other symbol applied to the cap; and said cap being provided with a flap-covered opening through which the fuse may be viewed by lifting the flap.

An additional object is to provide a protection for the top of the fuse plug to prevent the accumulation of dust or other extraneous material from obscuring the fuse plug window through which the fuse may be viewed.

I attain these and other objects by the devices and arrangements illustrated in the accompanying drawing, in which- Fig. 1 is a side elevation of an electric fuse plug showing, in section, my cover or cap applied thereto; Fig. 2 is a plan view of my improved fuse plug cap; and Fig. 3 is a perspective view thereof.

Similar numerals of reference refer to similar parts throughout the several views.

Referring to the drawing, it will be seen that the fuse plug I is provided with a head 2. This head 2 is provided with a transparent central window (not shown) through which the fuse itself may be seen. My improved cap comprises a rubber disk 3 with a down-turned flange 4 extending partially or wholly around the disk, said flange 4 being adapted to grip the edge of the head 2 to hold the cap in place on the plug. The flange 4 also acts as a means of giving the fingers a rmer grip on the plug I when screwing or unscrewing it in its socket.

The disk 3 is provided with a cut 5, which may be arcuate in form, by means of which the ap 6 is formed, said flap 6 being an integral part of the disk 3 and joined thereto by the uncut neck l.

The flap is provided with an identifying number, or other symbol, 8 which may be printed on a sticker 9 of paper, or other suitable material, secured to the flap 6 by a suitable adhesive, or it may be formed in the flap 6 by any suitable means.

I plan to have the caps arranged in pairs, each cap of a pair having the same identifying number. In practice the caps will be sold in sets, each set having several pairs of caps and each pair having a different number.

rIhus it will be seen that if a circuit known as #2 goes dead, it is only necessary to inspect the fuse plugs which have the caps with #2 on them, to determine which plug has been burnt out, by lifting the flaps 6 of both of said two caps and viewing the fuses therein through the openings thus formed. The destroyed fuse plug may then be unscrewed from its socket, the cap removed therefrom and placed on a new plug which is then screwed in :the empty socket.

Variations of my invention may, of course, be made within the limits as defined by the following claims.

Having described my invention, what I claim and desire to secure by Letters Patent, is:

1. A removable cap adapted to cover the exterior of a completed fuse plug comprising a disk, having a down-turned flange adapted to removably clasp the head of the fuse plug.

2. A removable cap adapted to cover the exterior of a complete fuse plug comprising a disk of insulating material, having a resilient downturned flange adapted to removably clasp the head of the fuse plug.

3. A removable cap adapted to cover the exterior of a completed fuse plug comprising a disk of flexible material having an integral portion thereof partially out to form a liftable flap, forming a hole through the disk when the iiap is lifted, said disk having a down-turned ange adapted to removably clasp the head of the fuse plug.

4. A removable cap adapted to cover the exterior of a completed fuse plug having a downturned resilient flange adapted to removably clasp the head of the fuse plug, and having an identifying symbol thereon.

ROBERT THORNE BRI'ITAIN. 

